Random Access on Multipacket Reception Channel with Applications to Satellite Communications Open Access
- Other title
Medium Access Control
- Type of item
- Degree grantor
University of Alberta
- Author or creator
- Supervisor and department
Schlegel, Christian (Electrical and Computer Engineering, Dalhousie University)
Khabbazian, Majid (Electrical and Computer Engineering)
- Examining committee member and department
Fair, Ivan (Electrical and Computer Engineering)
Jiang, Hai (Electrical and Computer Engineering)
Ghaderi, Majid (Computer Science, University of Calgary)
Department of Electrical and Computer Engineering
- Date accepted
- Graduation date
Doctor of Philosophy
- Degree level
In the field of multiple-access systems, multipacket reception (MPR) is defined as the capability of the receiver to successfully receive/decode concurrent packets from multiple transmitters. While physical-layer capabilities and limitations of MPR-capable systems using technologies such as code-division multiple-access (CDMA) and multiple-antenna communications are well studied in the literature, an important question is how this capability affects the performance at the medium-access control (MAC) layer. Random access on the MPR channel is studied in this thesis. First, we study throughput of Aloha random access with Poisson arrivals and highlight the throughput advantage of the MPR channel compared to the conventional collision channel. The analysis shows that Aloha performs more efficiently on the MPR channels where the maximum number of concurrent transmissions that can be received by the receiver is larger providing that the aggregate traffic on the medium is controlled and maintained below a threshold. If the average number of transmissions exceeds this threshold, however, the system throughput declines rapidly, which motivates efficient control mechanisms on top of random access. Bounds on the throughput performance of random access are examined and a closed-form approximation for throughput of genie-aided random access with Poisson arrivals is derived. A method of computing the optimal access probability is, then, presented for the cases where only partial information about contention on the medium is available. Next, we examine a finite-size multiple-access system where the incoming traffic is the aggregate of interrupted on/off Markov sources. The resulting system is a Markov decision process for which the optimal access algorithm is provided and compared to lower and upper bounds. A new rate/burstiness model of an on/off Markov source is proposed, which is used to present where the throughput curves lay compared to the computed bounds. Furthermore, it is shown that the gap between the upper and lower bounds reduces as the maximum number of packets that can be received increases. Queuing analysis is provided and closed-form equations for queuing delay as a function of throughput are derived. While the above algorithm requires prior knowledge of traffic parameters, we also propose a framework for more practical random access systems where no prior knowledge of traffic and node population is available. The proposed scheme uses the theory of extended Kalman filters in order to track the contention on the medium and select the near-optimal access probability. The proposed scheme is shown to stabilize the operating point of the multiple-access system close to the point where throughput of Aloha takes its maximum. This scheme is also examined for unideal cases such as delayed acknowledgement channel and shown to be a robust access scheme on the MPR channel. Finally, we study two aspects of random access on the MPR channel that are related to satellite communications. First, a repetition random access scheme that employs transmission diversity and iterative collision resolution is analyzed for the case of MPR channels. Asymptotic analysis for this generalized model is provided and it is shown that larger loads can be supported in smaller frames. Next, throughput-delay tradeoff of random access over delayed links is analyzed and scaling laws are derived for the cases of the collision channel and the MPR channel as well as repetition random access. It is shown that multiuser detection and repetition schemes improve the multiple access performance in the sense that the inevitable compromise between throughput and delay is mitigated by joint detection capabilities and/or repetitions.
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
- Citation for previous publication
M. Ghanbarinejad and C. Schlegel, “Distributed Probabilistic Medium Access with Multipacket Reception and Markovian Traffic,” Telecommunication Systems, vol. 56, no. 2, pp. 311-321, June 2014.
- Date Uploaded
- Date Modified
- Audit Status
- Audits have not yet been run on this file.
File format: pdf (PDF/A)
Mime type: application/pdf
File size: 830243
Last modified: 2015:10:18 01:36:28-06:00
Original checksum: 89d4e3f1f00493031046069197146e30
Activity of users you follow